Noise Models, Denoising Filters and Applications
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Blind Denoising Autoencoder
1 Blind Denoising Autoencoder Angshul Majumdar In recent times a handful of papers have been published on Abstract—The term ‘blind denoising’ refers to the fact that the autoencoders used for signal denoising [10-13]. These basis used for denoising is learnt from the noisy sample itself techniques learn the autoencoder model on a training set and during denoising. Dictionary learning and transform learning uses the trained model to denoise new test samples. Unlike the based formulations for blind denoising are well known. But there has been no autoencoder based solution for the said blind dictionary learning and transform learning based approaches, denoising approach. So far autoencoder based denoising the autoencoder based methods were not blind; they were not formulations have learnt the model on a separate training data learning the model from the signal at hand. and have used the learnt model to denoise test samples. Such a The main disadvantage of such an approach is that, one methodology fails when the test image (to denoise) is not of the never knows how good the learned autoencoder will same kind as the models learnt with. This will be first work, generalize on unseen data. In the aforesaid studies [10-13] where we learn the autoencoder from the noisy sample while denoising. Experimental results show that our proposed method training was performed on standard dataset of natural images performs better than dictionary learning (K-SVD), transform (image-net / CIFAR) and used to denoise natural images. Can learning, sparse stacked denoising autoencoder and the gold the learnt model be used to recover images from other standard BM3D algorithm. -
A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers
Sensors 2011, 11, 9233-9241; doi:10.3390/s111009233 OPEN ACCESS sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Article A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers Albert Canagasabey 1,2,*, Andrew Michie 1,2, John Canning 1, John Holdsworth 3, Simon Fleming 2, Hsiao-Chuan Wang 1,2 and Mattias L. Åslund 1 1 Interdisciplinary Photonics Laboratories (iPL), School of Chemistry, University of Sydney, 2006, NSW, Australia; E-Mails: [email protected] (A.M.); [email protected] (J.C.); [email protected] (H.-C.W.); [email protected] (M.L.Å.) 2 Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, 2006, NSW, Australia; E-Mail: [email protected] (S.F.) 3 SMAPS, University of Newcastle, Callaghan, NSW 2308, Australia; E-Mail: [email protected] (J.H.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +61-2-9351-1984. Received: 17 August 2011; in revised form: 13 September 2011 / Accepted: 23 September 2011 / Published: 27 September 2011 Abstract: Linewidth measurements of a distributed feedback (DFB) fibre laser are made using delayed self heterodyne interferometry (DHSI) with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are wL (MZI) = (1.6 ± 0.2) kHz and wL (MI) = (1.4 ± 0.1) kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. -
Suburban Noise Control with Plant Materials and Solid Barriers
Suburban Noise Control with Plant Materials and Solid Barriers by DAVID I. COOK and DAVID F. Van HAVERBEKE, respectively professor of engineering mechanics, University of Nebraska, Lin- coln; and silviculturist, USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo. ABSTRACT.-Studies were conducted in suburban settings with specially designed noise screens consisting of combinations of plant inaterials and solid barriers. The amount of reduction in sound level due to the presence of the plant materials and barriers is re- ported. Observations and conclusions for the measured phenomenae are offered, as well as tentative recommendations for the use of plant materials and solid barriers as noise screens. YOUR$50,000 HOME IN THE SUB- relocated truck routes, and improved URBS may be the object of an in- engine muffling can be helpful. An al- vasion more insidious than termites, and ternative solution is to create some sort fully as damaging. The culprit is noise, of barrier between the noise source and especially traffic noise; and although it the property to be protected. In the will not structurally damage your house, Twin Cities, for instance, wooden walls it will cause value depreciation and dis- up to 16 feet tall have been built along comfort for you. The recent expansion Interstate Highways 35 and 94. Al- of our national highway systems, and though not esthetically pleasing, they the upgrading of arterial streets within have effectively reduced traffic noise, the city, have caused widespread traffic- and the response from property owners noise problems at residential properties. has been generally favorable. -
Realisation of the First Sub Shot Noise Wide Field Microscope
Realisation of the first sub shot noise wide field microscope Nigam Samantaray1,2, Ivano Ruo-Berchera1, Alice Meda1, , Marco Genovese1,3 1 INRIM, Strada delle Cacce 91, I-10135 Torino, ∗Italy 2 Politecnico di Torino, Corso Duca degli Abruzzi, 24 - I-10129 Torino, Italy and 3 INFN, Via P. Giuria 1, I-10125 Torino, Italy ∗ ∗ Correspondence: Alice Meda, Email: [email protected], Tel: +390113919245 In the last years several proof of principle experiments have demonstrated the advantages of quantum technologies respect to classical schemes. The present challenge is to overpass the limits of proof of principle demonstrations to approach real applications. This letter presents such an achievement in the field of quantum enhanced imaging. In particular, we describe the realization of a sub-shot noise wide field microscope based on spatially multi-mode non-classical photon number correlations in twin beams. The microscope produces real time images of 8000 pixels at full resolution, for (500µm)2 field-of-view, with noise reduced to the 80% of the shot noise level (for each pixel), suitable for absorption imaging of complex structures. By fast post-elaboration, specifically applying a quantum enhanced median filter, the noise can be further reduced (less than 30% of the shot noise level) by setting a trade-off with the resolution, demonstrating the best sensitivity per incident photon ever achieved in absorption microscopy. Keywords: imaging, sub shot noise, microscopy, parametric down conversion 1 INTRODUCTION Sensitivity in standard optical imaging and sensing, the ones exploiting classical illuminating fields, is fundamentally lower bounded by the shot noise, the inverse square root of the number of photons used. -
Noise Reduction Technologies for Turbofan Engines
NASA/TM—2007-214495 Noise Reduction Technologies for Turbofan Engines Dennis L. Huff Glenn Research Center, Cleveland, Ohio September 2007 NASA STI Program . in Profile Since its founding, NASA has been dedicated to the • CONFERENCE PUBLICATION. Collected advancement of aeronautics and space science. The papers from scientific and technical NASA Scientific and Technical Information (STI) conferences, symposia, seminars, or other program plays a key part in helping NASA maintain meetings sponsored or cosponsored by NASA. this important role. • SPECIAL PUBLICATION. Scientific, The NASA STI Program operates under the auspices technical, or historical information from of the Agency Chief Information Officer. It collects, NASA programs, projects, and missions, often organizes, provides for archiving, and disseminates concerned with subjects having substantial NASA’s STI. The NASA STI program provides access public interest. to the NASA Aeronautics and Space Database and its public interface, the NASA Technical Reports Server, • TECHNICAL TRANSLATION. English- thus providing one of the largest collections of language translations of foreign scientific and aeronautical and space science STI in the world. technical material pertinent to NASA’s mission. Results are published in both non-NASA channels and by NASA in the NASA STI Report Series, which Specialized services also include creating custom includes the following report types: thesauri, building customized databases, organizing and publishing research results. • TECHNICAL PUBLICATION. Reports of completed research or a major significant phase For more information about the NASA STI of research that present the results of NASA program, see the following: programs and include extensive data or theoretical analysis. Includes compilations of significant • Access the NASA STI program home page at scientific and technical data and information http://www.sti.nasa.gov deemed to be of continuing reference value. -
Journey to a Quiet Night
QUIET NIGHT TOOLKIT Journey to a Quiet Night Strategies to Reduce Hospital Noise and Promote Healing Patient responses to the HCAHPS survey of experience consistently identify noise at night as a dissatisfier in their hospital stay. Only 51% of patients surveyed following discharge from a California hospital report that their hospital room was always quiet at night, compared to 62% of patients nationally. Noise at night is our greatest challenge to create a healing environment of care. Hospitals that have successfully improved this dimension of care have used a few common strategies: informed staff behavior modification, mechanical noise mitigation, environmental noise mitigation, and real time data to drive changes. Drivers for Improvement in Hospital Noise • Educate staff about effects of noise on patient healing Informed Behavior • Engage staff in remediation plan development Modifi cation • Monitor noise in real time HCAHPS Score for “Always Quiet at Night” • “Quiet kits” for patients Mechanical above national average of • Equipment repair Mitigation • Noise absorbing panels or curtains in high traffi c areas AIM • Establish “quiet hours” Environmental 62% • Visual cues, such as signs and dimmed lights at night in patient care areas Mitigation • Utilize white noise options Real Time • Develop system of real time alerts based on patient/family input/feedback Data Learning • Real time reporting mechanism with feedback loop Informed behavior Modifi cation As health care providers, it is imperative that we understand and help to provide our patients with an environment that is optimized for healing. Staff members must be educated about the effects that noise from talking, equipment and other activities has on patients’ healing in the hospital. -
Survey of Noise in Image and Efficient Technique for Noise Reduction
International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2015): 78.96 | Impact Factor (2015): 6.391 Survey of Noise in Image and Efficient Technique for Noise Reduction Arti Singh1, Madhu2 1, 2Research Scholar, Computer Science, BBAU University, Lucknow , Uttar Pradesh, India Abstract: Removing noise from the image is big challenge for researcher because removal of noise in image causes the artifacts and image blurring. Noise occurred in image during the time of capturing and transmission of the image. There are many methods for noise removal from the images. Many algorithms and techniques are available for removing noise from image, but each method exist their own assumptions, merits and demerits. Noise reduction algorithms for remove noise is totally depends on what type of noise occur in the image. In this paper, focus on some important type of noise and noise removal techniques is done. Keywords: Impulse noise, Gaussian noise , Speckle noise ,Poisson noise, mean filter, median filter ,etc 1. Introduction or over heated faulty component can cause noise arise in image because of sharp and sudden changes of Digital image processing is using of algorithms for image signal. 퐼 푖, 푗 푥 < 푙 improve quality order of digital image .This error on 퐼푠푝 푖, 푗 = image is called noise in image which do not reflect real 퐼푚푖푛 + 푌 퐼푚푎푥 −퐼푚푖푛 푥 > 푙 intensities of actual scene. There are two problems found x,y∈[0,1] are two uniformly distributed random variables in image processing: Blurring and image noise. Noise image occurred by many reasons: When we capture image from camera (scratches are available in camera). -
All You Need to Know About SINAD Measurements Using the 2023
applicationapplication notenote All you need to know about SINAD and its measurement using 2023 signal generators The 2023A, 2023B and 2025 can be supplied with an optional SINAD measuring capability. This article explains what SINAD measurements are, when they are used and how the SINAD option on 2023A, 2023B and 2025 performs this important task. www.ifrsys.com SINAD and its measurements using the 2023 What is SINAD? C-MESSAGE filter used in North America SINAD is a parameter which provides a quantitative Psophometric filter specified in ITU-T Recommendation measurement of the quality of an audio signal from a O.41, more commonly known from its original description as a communication device. For the purpose of this article the CCITT filter (also often referred to as a P53 filter) device is a radio receiver. The definition of SINAD is very simple A third type of filter is also sometimes used which is - its the ratio of the total signal power level (wanted Signal + unweighted (i.e. flat) over a broader bandwidth. Noise + Distortion or SND) to unwanted signal power (Noise + The telephony filter responses are tabulated in Figure 2. The Distortion or ND). It follows that the higher the figure the better differences in frequency response result in different SINAD the quality of the audio signal. The ratio is expressed as a values for the same signal. The C-MES signal uses a reference logarithmic value (in dB) from the formulae 10Log (SND/ND). frequency of 1 kHz while the CCITT filter uses a reference of Remember that this a power ratio, not a voltage ratio, so a 800 Hz, which results in the filter having "gain" at 1 kHz. -
Performance Analysis of Spatial and Transform Filters for Efficient Image Noise Reduction
Performance Analysis of Spatial and Transform Filters for Efficient Image Noise Reduction Santosh Paudel Ajay Kumar Shrestha Pradip Singh Maharjan Rameshwar Rijal Computer and Electronics Computer and Electronics Computer and Electronics Computer and Electronics Engineering Engineering Engineering Engineering KEC, TU KEC, TU KEC, TU KEC, TU Lalitpur, Nepal Lalitpur, Nepal Lalitpur, Nepal Lalitpur, Nepal [email protected] [email protected] [email protected] [email protected] Abstract—During the acquisition of an image from its systems such as laser, acoustics and SAR (Synthetic source, noise always becomes integral part of it. Various Aperture Radar) images [3]. algorithms have been used in past to denoise the images. Image denoising still has scope for improvement. Visual This paper introduces different types of noise to be information transmitted in the form of digital images has considered in an image and analyzed for various spatial become a considerable method of communication in the and transforms domain filters by considering the image modern age, but the image obtained after transmission is metrics such as mean square error (MSE), root mean often corrupted due to noise. In this paper, we review the squared error (RMSE), Peak Signal to Noise Ratio existing denoising algorithms such as filtering approach (PSNR) and universal quality index (UQI). and wavelets based approach, and then perform their comparative study with bilateral filters. We use different II. BACKGROUND noise models to describe additive and multiplicative noise The Wavelet Transform (WT) is a powerful tool of in an image. Based on the samples of degraded pixel signal and image processing, which has been neighborhoods as inputs, the output of an efficient filtering successfully used in many scientific fields such as signal approach has shown a better image denoising performance. -
Nasa Tm- 77750 Nasa Technical Memorandum Nasa Tm-77750
NASA TM- 77750 NASA TECHNICAL MEMORANDUM NASA TM-77750 NASA-TM-77750 19850004171 PATTERNS OF BEHAVIOD<TN LODGINGS EXPOSED TO TRAFFIC NOISE Jacques Lambert, Francois Simonnet Translation of "Comportements dans l'habitat soumis au bruit de circulation". Institut de Recherche des Transports, Arcueil, France, Rapport de Recherche I.R.T. No. 47, September, 1980, pp 1-145. 11.,. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON D.C. 20546 NOVEMBER 1984 • • \ IT........ f.n.• PM. ,. II. 0 ... I. .M.,...·.c.......... NAS1\. TM.,-77750 .. , ...... S....... PATTERNS or' BEHAVIOR IN I. • .,.,. hie November, 1984 TF~FFIC LODGINGS EXPOSED TO NOISE • •. ,.,te-t". 0, ee. 70 A.......c.. I. ''''e''''. 0. H.. Jacques Lambert, Francois Simonnet 11...... "-'..... '. 1-------------------------1... e.......... 0......... t. ' .......... 0,.......'... N... et4 ........ MAS... .~C; 42 SCITRAN • lox S4S6 .' II. ,,,..,......., ...c.....4 r.__ • a _..,.... ClI·un. 'rraul.t1oll, 12. SU4t1~&:r"&;rD_==_ .. Sp.at MaiIliat~.t.io.....-----------..f VUD1qtOD. D~Ce ~0546 No Ate-f c... I'" ...........,.......Translatlon. .. of "COITInortements dans l'habltat. soumis au bruit de circulation".'" Institut de·Recherche des Transports, Arcuei1, France, Rapport de Recherche' I ~R •. ~.· No. 47, September, 1980, pp. 1-145. , .. M ......· Thresho1c values at which public services should intervene ~o attenuate the noise nuisance are defined. Observations were made in the field of daily life at .. home. Data was collecte<J. on the use of loe1gings, on effects of noise on health and sleep~ and on the incidence of running away from home. A correlation was made also with the equipment. and noise insulation of lodgings. The results s.how that abov.eGG dB in daytime, there are behavior patterns that are extreme so far as they modify in a considerable manner the way bf, life of-people, living in both collective housing Capartments) and in individual houses • • ~. -
Estimation from Quantized Gaussian Measurements: When and How to Use Dither Joshua Rapp, Robin M
1 Estimation from Quantized Gaussian Measurements: When and How to Use Dither Joshua Rapp, Robin M. A. Dawson, and Vivek K Goyal Abstract—Subtractive dither is a powerful method for remov- be arbitrarily far from minimizing the mean-squared error ing the signal dependence of quantization noise for coarsely- (MSE). For example, when the population variance vanishes, quantized signals. However, estimation from dithered measure- the sample mean estimator has MSE inversely proportional ments often naively applies the sample mean or midrange, even to the number of samples, whereas the MSE achieved by the when the total noise is not well described with a Gaussian or midrange estimator is inversely proportional to the square of uniform distribution. We show that the generalized Gaussian dis- the number of samples [2]. tribution approximately describes subtractively-dithered, quan- tized samples of a Gaussian signal. Furthermore, a generalized In this paper, we develop estimators for cases where the Gaussian fit leads to simple estimators based on order statistics quantization is neither extremely fine nor extremely coarse. that match the performance of more complicated maximum like- The motivation for this work stemmed from a series of lihood estimators requiring iterative solvers. The order statistics- experiments performed by the authors and colleagues with based estimators outperform both the sample mean and midrange single-photon lidar. In [3], temporally spreading a narrow for nontrivial sums of Gaussian and uniform noise. Additional laser pulse, equivalent to adding non-subtractive Gaussian analysis of the generalized Gaussian approximation yields rules dither, was found to reduce the effects of the detector’s coarse of thumb for determining when and how to apply dither to temporal resolution on ranging accuracy. -
Noise Assessment Activities
Noise assessment activities Interesting stories in Europe ETC/ACM Technical Paper 2015/6 April 2016 Gabriela Sousa Santos, Núria Blanes, Peter de Smet, Cristina Guerreiro, Colin Nugent The European Topic Centre on Air Pollution and Climate Change Mitigation (ETC/ACM) is a consortium of European institutes under contract of the European Environment Agency RIVM Aether CHMI CSIC EMISIA INERIS NILU ÖKO-Institut ÖKO-Recherche PBL UAB UBA-V VITO 4Sfera Front page picture: Composite that includes: photo of a street in Berlin redesigned with markings on the asphalt (from SSU, 2014); view of a noise barrier in Alverna (The Netherlands)(from http://www.eea.europa.eu/highlights/cutting-noise-with-quiet-asphalt), a page of the website http://rumeur.bruitparif.fr for informing the public about environmental noise in the region of Paris. Author affiliation: Gabriela Sousa Santos, Cristina Guerreiro, Norwegian Institute for Air Research, NILU, NO Núria Blanes, Universitat Autònoma de Barcelona, UAB, ES Peter de Smet, National Institute for Public Health and the Environment, RIVM, NL Colin Nugent, European Environment Agency, EEA, DK DISCLAIMER This ETC/ACM Technical Paper has not been subjected to European Environment Agency (EEA) member country review. It does not represent the formal views of the EEA. © ETC/ACM, 2016. ETC/ACM Technical Paper 2015/6 European Topic Centre on Air Pollution and Climate Change Mitigation PO Box 1 3720 BA Bilthoven The Netherlands Phone +31 30 2748562 Fax +31 30 2744433 Email [email protected] Website http://acm.eionet.europa.eu/ 2 ETC/ACM Technical Paper 2015/6 Contents 1 Introduction ...................................................................................................... 5 2 Noise Action Plans .........................................................................................